Shrinkproofing wool through serial impregnation with a diisocyanate having one or two terminal ester groups and a diamine



United; States Patent Office 3,35?,785 Patented Dec. 12, i967 Thisinvention relates to the treatment of fibers and textile materials madefrom them. More particularly it relates. to a method for shrinkproofingwool utilizing alipthatic diisocyanates of carboxylic and dicarboxylicacid esters, novel compositions containing the same, and

novel products obtained thereby.

There are at least two mechanisms by which the shrinkage of wool mayoccur. The first of these is known as relaxation shrinkage and occurswhen wool is treated with water or other chemicals. The art hasattempted to solve the relaxation shrinkage problem by submitting woolto preshrinking wherein the material is allowed to encounter theenvironment which it would normally encounter during use and thereby bepreshrunk before being put into actual use. It is theorized that thisshrinkage is due to a change in the internal structure of the woolfibers. Another important shrinkage phenomenon, designated feltingshrinkage, occurs in consequence of the physical structure of woolfibers. Wool fibers, which are normally clad with scales, will shrinkwhen friction is applied to the wetted wool. The fibers are apparentlyaligned in random directions and the movement induced in these fiberstends, by a mechanism involving differential friction, to shrink thematerial. The arthas attempted to control felting shrinkage mainly bythree techniques. Two of these, the oxidative and hydrolytic methods,involve treating the wool chemically with such materials as hypochloriteor chlorine in the first case, or with proteolytic enzymes such astrypsin and papain in the second. These two processes both suffer thedisadvantage of degrading the wool to a point where, in order to achieveeffective shrinkproofing, the material is consequently weakened instrength. Both of these methods alter the scale formation on the woolfibers.

Another method which has been directed toward the control of feltingshrinkage is the so-called polymer deposition method. This involvesdepositing upon the wool fibers a polymer which tends to decrease theshrinkage of the wool when the material is subjected to a normallyshrinking environment. Heretofore, the conventional polymer depositiontechniques have not been entirely satisfactory, all suffering from oneor more disadvantages which seriously limit their commercial acceptance.For example, some polymer systems currently available to the art requirethe use of large amounts of solvents for the. deposition of the polymer.This is a very serious drawback to the Wool processor who is generallynot equipped to handle solventsboth from the standpoints of safety andeconomy. Another disadvantage attending the polymer deposition processis the. relatively large amounts of.

polymer required to be deposited. This too, as can be readilyappreciated, presents an economic barrier to the. wool processor.Further, conventional polymer .deposition techniquestend to stiffen andharshen the wool such that the material does not conform aestheticallyto a de-;

sirable standard.

When the disadvantages of the prior processes are com sidered it isapparent that it would be extremely desirable does not require the useof organic solvents and large amounts of polymer deposition and whichyields a wool which is not harsh to the touch or stiffened to anyappreciable extent.

It is accordingly an object of this invention to provide a process forshrinkproofing wool which does not require the use of organic solvents.

It is a further object of the invention to compositions useful inshrinkproofing wool.

Yet. another object of the invention is to provide a process forshrinkproofing Wool whereby the wool so treated is not harsheued to anyappreciable extent.

It is still a further objectof the invention to provide a process forshrinkproofing woolby the in situ formation and depoistion of a polyureawhich does not tend to discolor upon prolonged exposure to light.

provide novel These and further objects will become more apparent.

when full consideration is given to the following detailed disclosure.

In accordance with the present invention it has been discovered thatwool may be very effectively shrinkproofed by the in situ formationthereon of a polyurea formed from a water dispersible diarnine and amember of a particular class of diisocyanates. The inventioncontemplates novel processes for forming the novel polyurea, noveldiisocyanate compositions used in the novel processes and novelshrinkproofed articles obtained thereby. The process involves seriallyimpregnating wool with the diisocyanate and the diarnine, notnecessarily, but preferably, in that order. The diarnine coming into.contact with the diisocyanate, reacts therewith forming the polyureapolymer as a coating on the wool fibers, though residual amino groups ofthe wool also co-react, yielding a grafted polymer structure.

It isan important feature of the invention that the for mation of thepolyurea does not involve the use of an organic solvent but rather usesan aqueous system for the application to the wool fibers of thereactants which form: the polyurea. In this regard, it is critical thatthe diisocyanate be supplied to the wool in the form of an aqueousemulsion and the diarnine in the form of an aqueous dispersion. As usedherein, dispersion is meant to include solutions.

The diisocyanates contemplated for use in this inven-.

tion are diisocyanato substituted aliphatic monocarboxylic acid estersor dicarboxylic acid esters of the following either unsubstituted orsubstituted with halogen radicals,=

R is a lower alkylene or a lower alkylidene radical, R can be eitherhydrogen, or the radical.

Typical of the diisocyanates represented by the fore-1 going formulaare: the esters of 2,6-diisocyanato caproic acid (lysine .diisocyanate)such :as the methyl, ethyl,

propyl, butyl, octyl, dodecyL stearyl, methoxymethyLfl methoxyethyl,'y-ethoxypropyl, phenyl, benzyl, o-tolyl, o- (2 chlorotolyl), 2bromoethyl, 1,2-dichloropropyl, 2,3- dichloropropyl, and isopropylesters; the esters of 2,5-diisocyanato valeric acid (ornithinediisocyanate) such as.

ethyl, propyl, butyl, hexyl, octyl, dodecyl, stearyl, ethoxymethol,B-ethoxyethyl, phenyl, benzyl, o-tolyl, o-(2-chlorotolyl),2-chloropropyl, 2,3-dichloropropyl and isopropyl esters;.the diesters of2,4-diisocyanato glutaric acid, 2,5-.

diisocyanato adipic acid, 2,6-diisocyanato pimelic acid,2,7-diisocyanato suberic acid, 2,9diisocyanato sebacic acid such as thedimethyl, diethyl, dipropyl, dibutyl, dioctyl, distearyl, diphenyl,dibenzyl, di(o-tolyl), di(o-(2- chlorotolyl) di(2 chloropropyl), di(2,3dichloropropyl), and diisopropyl diesters and mixed diesters such asmethyl-propyl diesters, phenyl-octyl diesters, and benzylstearyldiesters. The diisocyanates may be either the levo rotatory forms or thedextro rotatory forms, racemates or mixtures thereof. The diisocyanatespreferred for use are the methyl and octyl esters of 2,6-diisocyanatocaproic acid and most preferably the octyl ester.

The diamines contemplated for use in the invention are the waterdispersible diamines or water dispersible salts of water insolublediamines. In general, any diamine conforming to the abovecharacteristics will be suitable but it is preferred to use diaminessuch as hexamethylencdiamine; alkyl esters of lysine or omithine intheir water soluble dihydrohalide salt form such as n-octyl-L-lysinatedihydrochloride or n-hexyl ornithinate dihydrochloride; tetramethylenediamine, trimethylene diamine; piperazine, methyl anddimethylpiperazine; a,w-diamino polypropylene oxide; mixtures of theabove; and the like. Most preferred among the foregoing ishexamethylenediamine.

Before embarking upon a discussion of the nature and characteristics ofthe diisocyanate emulsion and diamine dispersion, for purposes ofclarity of presentation, the following, which is a description of thegeneral mode of carrying out the process, is presented. In general, thewool is first impregnated with the diisocyanate emulsion so as toprovide throughout the wool an amount of diisocyanate. The impregnatedwool is then removed from the aqueous emulsion of the diisocyanate andpressed between rollers so as to remove excess moisture and materials.The thus obtained material is then introduced into the diaminedispersion, therein to come in contact with the diamine itself. Thereaction between the diamine and the diisocyanate is very rapid at roomtemperature with the consequent formation of the polyurea correspondingto the diamine and diisocyanate.

After the polymerization reaction is complete the resultin g woolenmaterial is wrung to recover unreacted diamine or diisocyanate as thecase may be, and the impregnated piece then washed to remove any excessmaterials such as free polymer or any other diamine or diisocyanate notexpressed in the wringing stage. The material is then ready forprocessing as desired, such as drying, dyeing, and the like.

In general, for effective shrinkproofing, it is desired to have on thewool and available for conversion to the polyurea between 0.1 and byweight of the diisocyanate and preferably from 0.5 to 4 weight percentbased on the weight of wool. This can be obtained by proper adjustmentof diisocyanate concentration in the emulsion. This concentration isapproximately linearly related to diisocyanate takeup on the wool. Inits preferred aspect the wool should take up between 80-100 weightpercent of total emulsion based on weight of wool. Therefore, theconcentration of the diisocyanate in the emulsion will be approximatelythe same as those given in connection with the desired amount to beimpregnated, namely from 0.1 to 10% by weight and preferably from 0.5 to4% by weight of the diisocyanate in water.

With further regard to the diisocyanate emulsion it is preferred toprovide a uniform distribution of diisocyanate through the aqueoussystem so that the resulting polyurea formed will be uniformlydistributed over the surface of the wool and will thus not be heavier inconcentration in one place than in another, which difference inconcentration might be visually apparent and would, therefore, detractfrom the aesthetic quality of the material. This may be achieved bymechanically dispersing the diisocyanate in the water as by agitation,ultrasonic vibration, the addition of emulsifiers, hereinafterdiscussed, and the like.

The temperature of the emulsion is not critical and is only a factor tothe extent that temperature affects the chemical stability of theemulsion. In this regard, it will be appreciated that since isocyanategroups react with water, there will be a finite time available to aprocessor during which a substantial amount of diisocyanate remainsunreaeted. This time will vary depending on the particular diisocyanateemployed. For the preferred diisocyanate herein, octyl 2,6-diisocyanatocaproate, the time is sufliciently long so that the emulsion isconveniently handled within 12 hours after its preparation. Operatingwithin this time, good results are obtained when the emulsion bathtemperature is between room temperature and about 40 C. Fordiisocyanates having a higher rate of reactivity, such as methyl 2,6liisocyanato caproate, lower bath temperatures are conveniently employedto retard the reactivity and allow the processor convenient time inwhich to impregnate the wool. Temperatures of the order of 5 to 15 C.are suitable for this purpose.

With regard to the length of time and the conditions under which thediisocyanate impregnates the wool, contact times in the ester bath arerelated to the physical state of the wool (fibers, yarn, fabric).Particular con sideration is given to the thickness of the weave and itsdensity. In general, the more dense the material the longer the contacttime necessary to impregnate the wool with a convenient amount ofdiisocyanate. In dealing with typical flannel suiting material goodresults are obtained when the contact time is between 10 and 60 seconds.Shorter contact times of the order of one second or less are suitablefor treating yarns and less dense materials, and longer times may benecessary for heavy fabrics.

With respect to the aqueous diamine dispersion it will be appreciated,as indicated previously, that the reaction between the diisocyanate andthe diamine is very rapid and occurs quite fast. at room temperature.For this reason the concentration of the diamine in the, aqueoussolution thereof is not critical. Since a one-to-one molar ratio ofdiamine to diisocyanate is required by the, stiochiometry it is, ofcourse, preferred to supply in the aqueous solution a sufficient amountof diamine to react with all the diisocyanate present in the wool. Forreasons of economy it is not desired to have an amount of diamine lessthan the stoichiometrically required amount. Hence the concentration ofthe diamine may be any convenient level consistent with these aims. Thetemperature and the contact time are not at all critical. Maintainingthe bath at a temperature of about room temperature to about 40 C. givessatisfactory results and as indicated above the reaction rate is veryrapid. Hence, the contacttime is of no criticality. Although thediscussion here has been provided with respect to carrying out thereaction in a batchwise operation it will be understood that the processas a whole is particularly amendable to continuous'operation and this istherefore the preferred mode of carrying it out.

Further, although the above description is directed to ward carrying outthe process by first impregnating with diisocyanate followed by thepolymerization reaction with the diamine, the process is not to belimited to such a sequence of operations. Indeed, the impregnation mayfirst be with the diamine dispersion, followed by polymerization throughthe use of the diisocyanate emulsion. When this order is carried out itwill be appreciated by those skilled in the art that a simple,straight-forward calculation will yield the amount of diamine present inthe first solution in order to obtain a wool article desirably havingbetween 0.1 and 10 weight percent of polyurea impregnated thereon. Thus,by working back from the amount of polyurea desired to be put on, onemay obtain the concentration of the diamine starting solution. The twobath process, in either order, is referredto as a serial treatmentherein.

In preparing the emulsion of the diisocyanate material the process isoperative when the diisocyanate is uniformly distributed in the watersystem without the aid; of any additives. However, when this is done theensuing operations should be carried outhastily so as to avoid settlingof the emulsion in the bath. As indicated previously, an.

emulsion of this type might not give uniform polymer deposition uponsubsequent reaction with diamine. For this reason it is preferred to addan emulsifying agent to aid in the emulsification of the diisocyanateinthe.

is not critical and will vary depending upon the particu lardiisocyanate employed as a starting, material. The

goal is to obtain a good emulsion which is non-settling within aconvenient operating time and one which gives.

good dispersion of particles throughout the medium. Hence any emulsifierwhich does this will be suitable. Thus it is even possible to use anemulsifier which may not be inert with respect to thediisocyanate but iselfective to form a good emulsion, if the rate of reaction between theemulsifier and the diisocyanate is not too rapid. In this regard, itwill be remembered that the diisocyanate, being in contact with water,itself undergoes some I reaction with the water. This is not detrimentalto the r process provided that the impregnation be carried out in suchtimeas will provide within the wool lattice a convenient amount ofunreacted diisocyanate. Withre-. gard to the amount of emulsifier used,it is convenient to use, for the preferred emulsifiers describedhereinafter,

about -15% by weight based on the diisocyanate. For i other materials,the total amount of emulsifier should. be enough to produce thedesirable emulsion and yet still be consistent with good reactioneconomics. The emulsifier may be added to, mixed, or blended with thediisocyanate prior to mixing with water. Such compositions of emulsifierand diisocyanate are novel.

In general, suitableemulsifying agents are as follows: Sodium laurylsulfate,: Ivory soap, sodium-N-methyl-N- oleoyl taurate (available underthe trade name Igepon T-77 from Antara Chemical Company), octyl phenylpolyethoxy ethanol (available under the trade name Triton Xl5 fromRohm &Haas Co.), isooctyl phenyl polyethoxy. ethanol (available under thetrade name Triton X-45 from: Rohm& Haas Co.). Also useful are variousother emulsifiers available under the Triton trade name such as TritonCF-Zl, Triton X 100, Triton X-405, Triton CF42, and Triton X-lS, many ofwhich are alkyl aryl polyethers; those available under the trade name Tergitol from Union Carbide Chemical Co. such as TergitoltNP 1X,Tergitol,

NP-27, Tergitol NPX, andTergitol NP-35, all of which are nonyl phenylpolyethylene glycol ethers.

In addition to the diisocyanates above, which are preferred, otherdiisocyanates and their adducts may also be used. For example, wheresome degree or yellowing can be tolerated, tolylene diisocyanate,phenylene diisocyanate or methylene bis-phenyl isocyanate may beemulsified and used in the serial treatment with a diamine. With thesemore reactive isocyanates it is necessary to maintain the emulsion bathat low temperatures (5-10 C. preferred) and to work with a shorthold-uptime to avoid premature polymer formation. Hexamethylenediisocyanate, which is a hazardous substanceto handle, is best convertedto an isocyanate-terminated adduct (with butylene glycol, hexamethyleneglycol and the like) before emulsification. Control of polymer rigidityis done via the choice of adductor choice of diamine.

In addition to their .efficacy as shrinkproofing :treatments, all theabove may find use in other textile finishing operations. Thus, byproper choice of monomers, useful and more or less permanent antistatic,water resistance,

or wash-and-wear characteristics may be introduced.

The following examples are given for purposes of illustration only andare not to be considered as limiting the invention. In each of thefollowing examples, unless;

otherwise indicated, the following test method is employed:

A wool cloth is dipped into,bath (1). After remaining in the bath for aperiod of timethe cloth is removed and passed twice through ahand-operatediwringer to remove excess material. It is then immersed inbath (2) and again i 1 passed twice through a wringer. The contact timefor each of the above immersions may vary from 15 to 30m 60 secondswithout any noticeable efi'ect in the shriukproofing obtained. The clothis then rinsed with water to remove unreacted monomers, emulsifier andunbound polymer and allowed to dry.

The test for shrinkage involves washing three to six pieces of woolmeasuring about 4 to 6 inches in a bowl of 0.1% solutionof Triton X-lOO(isooctyl phenyl poly-' ethoxy ethanol) available from Rohm & Haas Co.,at,40 C. for 20 minutes. The samples are oven dried at 60 C.

to constant weight. In each washing there is always at least oneuntreated piece included to serve as a control. Each of the pieces ismeasured before treatment and:after washing-drying for calculation ofarea shrinkage.

EXAMPLE 1 Octyl-1,6diisocyanato caproate g 2 Sodium lauryl sulfate g .25Water ml 250 r Hexamethylenediamine g 5 Water; "ml". 250 Shrinkage(area)13% (control 38%.).

EXAMPLE 2 Hexamethylenediamine g 5 Water -ml 250 Octyl-2,6-diisocyanatocaproate -g 2 Sodium lauryl sulfate g .25 Water ml 250 Shrinkage 17%(control 40%).

EXAMPLE. 3

Octyl-2,6-diisocyanato caproate g 4 Sodium lauryl sulfate g .25 Water ml250 Hexamethylenediamine g 5 Water ml 250 Shrinkage 6% (control 43%).

EXAMPLE 4 1 ()ctyl-2,6-diisocyanatocaproate g.. Triton X-l5 (Octylphenyl toxyethanol-Rohm &

Haas) g .5 Water ml 250 n-Octyl-L-lysinate.dihydrochloride: g 10 Sodiumcarbonate g 10 Water ml 250 Shrinkage 16% (control 42%).

EXAMPLE 5 I (1) Oc tyl-2,6-diisocyanato caproate g 2 Triton X-lS (octylphenyl polyethoxy ethanol- Rohm & Haas) (orTriton CF-21 (alkyl arylpolyether) v .25 Water "n Water n-Octyl-L-lysinate-dihydrochloride g 5Sodium carbonate g 5 Water ml' Shrinkage: 25% (control 41% EXAMPLE-6Methyl-2,6-diisocyanato caproate g 2 Triton X15 (octylphenyl polyethoxyethanol- Water I l 250 Hexamethylenediamine g 5 Water a ml 250 Shrinkage3% (control 34%).

EXAMPLE 7 Methyl-2,6-diisocyanato caproate g 2 Triton X-lS (octyl phenylcolyethoxy ethanol- Rohm and Haas) g .25

Water ml- 2.50

N-octyl-L-lysinate.dihydrochloride, g 5 Sodium carbonate g 5' Water m1250 Shrinkage 20% (control 38%).

EXAMPLES 8 THROUGHv 15 TABLE 1 .Shrinkage, Percent Emulsifier TreatedControl .Aquarex D.(Sodiun1 sultatesof higher fatty alcohols, availablefrom E, I. du Pont de Nemours & 00.).

Triton X-15 (octyliphenoxy ethano1).

. Sodium lauryl sulfate Trlton X-45 (isooctyl phenyl polyethoxyethanol).

Triton (IF-32 (aminepolyglycol eondensate). Triton- X'100 (isoootylphenyl poly ethoxy ethanol). I 1 Triton C'F-21 (alkyl'aryl'p'olyether)...

be H H H an O- ,0! fgwcncno w u emanate H 00 m @CDHNIO This. exampleshows the shringproofing ofi woolusing an. emulsion ofoctyl-2,6-diisocyanato caproate in water without the aid of anemulsifier.

System 1) below isv prepared by rapid agitation in a Waring Blendor, andused immediately after preparation as the first bath in treatment ofwool. System (2) is used as the second bath. Results are shown.

Octyl 2, 6-diisocyanato caproate g Hexamethylenediamine g Water W mlShrinkage 6% (control 44% Wool cloth showed some streaks of resin.

EXAMPLE 17 Following the procedure of Example 16, the following bath;components are employed. Shrinkage results are shown.

Octyl-2,6-diisocyanato caproate is mixed with the various emulsifiersshown in Table 2 below such that the emulsifier constitutes 10% byweight of the total mixture. The original isocyanate content is measuredand compared with the final isocyanate content of the mixture after ithas been allowed to stand for 76 days.

TABLE 2 Isooyanate Content in Weight Percent Time in Emulsifier DaysInitial Final Sodium. lauryl sulfate 24. 4 i 22.0 76 Triton (IF-21(alkyl aryl polyether)'. 24.4 21.9 76 Triton Ci -32v (amine, polyglyeolcondensate) 24. 4 20. 2 76 Tergitol N P-IX (nonyl phenyl polyethyleneglycol ether) 24. 4 22. 1 76 Tergitol N P-27 (nonyl phenylpolyethyleneglycol other) 24. 4 21. 7 76 Tergitol NPX (nonyl phenylpolyehtylone glycol ether) 24. 4 22. 0 76 Tergitol N P-35 (nonyl phonylpolyethylene glycol ether) 24. 4 20. 7 76 Eightydhtee days after initialformulation, each of the above mixtures is separately added to water(0.5 g. of mixture, 50g. water) and good emulsions are obtained.

The following examples are intended to be illustrative of thepreparation of the. diisocyanato esters used in the present invention.

EXAMPLE 19 2,6.-diisocyanato methyl caproate 250 g. oflysinemonohydrochloride suspended in 2500 ml. ofl absolute methanol isdissolved by passing into the stirred. suspension dry hydrogen chloride.The reaction temperature, immediately goes up to 47 C. and in 10minutes. all the solids are dissolved. The gas is passed in for fiveminutes longer. The reaction mass is then permitted to cool slowly toroom temperature with stirring. Crystals start to form in 2.5 hours. Thereaction mass is stirred for a period of 15 hours at a temperatue, of 25C. The product is precipitated by adding 1.5 liters of diethyl etherover a period of 15 minutes. After one hour of stirring, the product isisolated by filtration and washing with three parts of ether dissolvedin two parts of methanol, followed by a diethyl ether wash. The productlysine dihydrochloride methyl ester is dried to constantweight at 65 C.in a vacuum oven.

The lysine methyl ester dihydrochloride is finely ground in a. mortarand 186 grams is suspended in 2100 ml. of

freshly dried and redistilled o-dichlorobenzene in a 3-neck flask.

Phosgene is passed into the reaction vessel at a rapid rate whileraising the temperature of the suspension to 150-155 C. As the reactionproceeds the solution becomes clearer and darker. Hydrogen chlorideevolution is indicated by fuming from the condenser as it hits the moistatmosphere. After twelve hours, no more hydrogen chloride evolves.Phosgene is passed in for one more hour and nitrogen is then bubbledthrough the reaction vessel as the solution temperature drops to 25 C.to remove residual phosgene and hydrogen chloride. The remaining solidsare removed by filtration and washed. The filtrate is then distilledunder reduced pressure. O-dichlorobenzene, the solvent, is distilled at44 C. and 2 mm. pressure. The product, 2,6-diisocyanato methyl caproate,is distilled at 123 C., at 0.45 mm. pressure. A clear, colorless liquidproduct is obtained having a refractive index of 1.4565 at 24.5 C.

In an analogous manner, the ethyl, propyl, butyl, or pentyl esters of2,6-diisocyanato caproic acid are prepared by substituting equivalentamounts of ethanol, propanol, butanol or pentanol for methanol in theforegoing procedure.

Similarly, when equivalent amounts of the monohydrochloride of2,5-diarnine valeric acid are substituted for lysine monohydroehlorideand equivalent amounts of methanol, ethanol, propanol, butanol orpentanol are employed as the alcohol in the foregoing procedure, thecorresponding methyl, ethyl, propyl, butyl or pentyl ester of2,5-diisocyanato valeric acid is obtained.

EXAMPLE 20 2,6-diisocyanato-n-ctyl caproate 18.2 g. (0.1 mole) ofl-lysine monohydrochloride is suspended in 140 ml. of n-octanolcontaining 0.24 mole of p-toluenesulfonic acid. The mixture is heateduntil water and octanol begin to distill and the reaction temperature isthen maintained at l20130 C. by addition of n-octanol. After 240 ml. ofn-octanol are added and removed over a two hour period, the residualalcohol is removed by vacuum stripping. The waxy product, thedi-p-toluenesulfonate salt of 2,6-diamino-n-octyl caproate, isrecrystallized from a mixture of ethanol and diethyl ether.

A solution of 73 grams of this product in 150 ml. methanol is adsorbedon a column of 500 ml. of a strongly basic styrene-divinylbenzene anionexchange resin (Dowex 1-X8) which had previously been activated on thehydroxyl cycle with aqueous ammonia, washed to neutrality, and had itswater displaced with methanol. The product is eluted from the columnwith methanol. The free base ester is not isolated but converted to thedihydrochloride recovered by precipitation with diethyl ether. Thedihydrochloride is suspended in 275 ml. of toluene and 0.45 mole ofphosgene added at 60-70" C. When evolution of HCl ceases, thetemperature of the reaction mass is gradually increased to strip out thesolvent. The product, 2,6-diisocyanato-n-octyl caproate is recovered byvacuum fractionation, B.P. 137-142 C. at 0.2 mm.

When the foregoing procedure is repeated using equivalent amounts ofhexanol, decanol, dodecanol, or tetradecanol in place of octanol, thecorresponding hexyl, decyl, dodecyl, or tetradecyl ester of2,6-diisocyanato caproic acid is obtained.

Similarly, when the foregoing procedure is repeated using equivalentamounts of the monohydroehloride of 2,5-diamino valeric acid in place ofthe lysine monohydrochloride and equivalent amounts of hexanol, octanol,decanol, dececanol, or tetradecanol are employed as the alcohol, thecorresponding hexyl, octyl, decyl, dodecyl or tetradecyl ester of2,5-diisocyanoto valeric acid is obtained.

. EXAMPLE 21 2,6-di'isocyanato phenyl caproate The acid chloride oflysine dihydrochloride is prepared by passing phosgene through asuspension of lysine dihydrochloride in dioxane for several hours at 50C. The oily product is added to dimethyl formamide containing thecalculated amount of sodium phenoxide to form the phenyl esters oflysine dihydrochloride. This ester is suspended along with a smallamount of sodium chloride, in o-dichlorobenzene (0.1 mole in 200 ml.)and phosgenated with gaseous phosgene at C. The resulting carbamylchloride is decomposed at C. and the solution is filtered, concentrated,treated with absorbent carbon, and the solvent removed to yield yellow2,6-diisocyanato phenyl caproate which was then purified by moleculardistillation.

When the foregoing procedure is repeated using equiva' lent amounts ofthe sodium salt of either o-cresol or 2,4,6 trichlorophenol in place ofthe sodium phenoxide, the o-tolyl or 1,3,5 trichlorophenyl ester of2,6-diisocyanato caprioc acid is obtained respectively.

Similarly, when equivalent amounts of ornithine dihydrochloride aresubstituted for the lysine dihydrochloride in the above procedure, thecorresponding 2,5- diisocyanato valeric acid esters are obtained.

It will be apparent to those skilled in the art that a wide variety ofcombinations and variations may be employed in preparing thecompositions of the present invention without departing from the spiritand scope of the invention. All such modifications, changes andvariations, departing from the above description are intended to beencompassed within the scope of the appended claims.

What is claimed is:

1. A process for the shrinkproofing of wool which comprises seriallyimpregnating wool with an aqueous emulsion and an aqueous diaminedispersion, said emulsion comprising water and a diisocyanate of theformula:

wherein R is selected from the group consisting of alkyl, alkoxy alkyl,aryl, alkaryl, aralkyl, and halogenated derivatives thereof, R isselected from the group consisting of lower alkylene or lower alkylideneand R is selected from the group consisting of hydrogen and the radical2. The process according to claim 1 wherein the aqueous emulsion of thediisocyanate additionally contains an emulsifier.

3. The process according to claim 1 wherein the diisocyanate isoctyl-2,6-diisocyanato caproate.

4. The process according to claim 3 wherein the diamine ishexamethylenediamine.

5. The process according to claim 4 wherein the aqueous emulsion ofoctyl-2,6-diisocyanato caproate additionally contains an emulsifier.

6. The process according to claim 5 wherein the emulsifier is selectedfrom the group consisting of sodium lauryl sulfate and alkyl arylpolyethers.

7. The process according to claim 6 wherein the emulsifier is sodiumlauryl sulfate.

8. The process according to claim 1 wherein the diisocyanate ismethyl-2,6-diisocyanato caproate.

9. The process according to claim 8 wherein the diamine ishexamethylenediamine.

1 1 1.2 10. The process according to claim 9 wherein the aque-References Cited ous emulsion of methyl-2g6-diisocyanato caproate addi-UNITED STATES PATENTS tionally contains an'emulsifier.

3;,084 ,019 4/1963: Whitfield ct al. 8-128 11. The process according toclaim 10 wherein the emulsifier is selected from the group consisting ofsodium. 5 V lauryl sulfate and alkyl aryl polyethers. NORMAN TORCHIN"Pnmary Exammer' 12. The process according to claim 10 wherein the I.CANNON Assistant Examiner.

emulsifier is sodium lauryl sulfate.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,357,785 December 12, 1967 John D. Garber et a1.

It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below. a a

Column 1, line 15, for "al1pthat1c read aliphatic column 2, line 14, for"depoistion" read deposition line 70, for "methol" read methyl column 6,line 23, for "Octyl-l,6-diisocyanato caproate" read Octyl-2,6diisocyanato caproate column 7, line 24, for "Triton X-lS (octyl phenylcolyethoxy ethanol" read Triton X-lS (octyl phenyl polyethoxy ethanolline 65, for "shringproofing" read shrinkproofing column 9, line 72, for"dececanol" read dodecanol Signed and sealed this 14th day of January1969.

(SEAL) Attest: Edward M. Fletcher, Ir. EDWARD J. BRENNER AttestingOfficer Commissioner of Patents

1. A PROCESS FOR THE SHRINKPROFFING OF WOOL WHICH COMPRISES SERIALLYIMPREGNATING WOOL WITH AN AQUEOUS EMULSION AND AN AQUEOUS DIAMINEDISPERSION, SAID EMULSION COMPRISING WATER AND A DIISOCYANATE OF THEFORMULA: